Oxygen breathing apparatus



Nov. 11, 71952 HOLLMANN 2,617,414

OXYGEN BREATHING APPARATUS Filed Jpne 3, 1949 3 Sheets-Sheet l Fig.7

2 27 w 26 so :1 2.9 20

I ////f l/ 1/ 79 24 23 22 27 Inventor 1952 F. HOLLMANN OXYGEN BREATHING APPARATUS 5 Sheets-Sheet 2 Filed June 3, 1949 lnvenfor Q W MW By --f Nov. 11, 1952 HQLLMANN 2,617,414

OXYGEN BREATHING APPARATUS Filed June 3, 1949 3 Sheets-Sheet 3 Patented Nov. 11, 1952 OXYGEN BREATHING APPARATUS Franz Hollmann, Lubeck, Germany, assignor to Otto Heinrich Drager, Lubeck, Germany Application June 3, 1949, Serial No. 96,887 In Germany October 1, 1948 7 Claims.

The present application relates to an air supply apparatus and a process for operating such an apparatus.

In known processes and apparatus of this type, an amount of air is supplied in accordance with the maximum requirements of the user, so that when the user is working at below maximum activity a considerable amount of air is wasted. Moreover, in such known devices no allowance is made for the varying capacities of different users, so that this factor also accounts for a large amount of oxygen waste in these known types of air-supply systems.

One of the objects of the present invention is to provide an apparatus and process for supplying air in which the flow of oxygen is determined solely by the needs of the user.

An additional object of the present invention is to provide an apparatus of the above type which supply apparatus having an expansible container which holds the breathing air therein. A first conduit means communicates with this container and conveys air to be inhaled to the user. A second conduit means communicates with the expansible container and conveys exhaled-air from the user back to the container. A scavenging device is mounted in the second conduit means for removing carbon dioxide from the exhaled air before it arrives back at the container. An oxygen tank is connected to a third conduit means which leads to the first conduit means for conveying fresh oxygen through the same to the container and to the user. A valve is mounted in the third conduit means for controlling the amount of oxygen removed from the tank, and an operating structure is connected to the valve and to the expansible container for controlling the valve by the movement of the container.

The apparatus also includes a pump having a flexible diaphragm extending across a chamber so as to divide the latter into first and second compartments. The first of these compartments is located in the third conduit means so that the oxygen released from the tank passes through this first compartment, nozzle means being provided in the third conduit means to cause the oxygen to build up a pressure in the first pump compartment. A fourth conduit communicates with the container and with the second compartment of the pump so as to convey air from this container to the second compartment, and apair of check valves are respectively mounted in the fourth conduit means, to prevent air from leaving the second compartment through this fourth conduit means, and on the second compartment to permit air to escape only from this second compartment to the outer atmosphere. The building up of pressure by the oxygen in the first compartment causes the diaphragm of the pump to compress air trapped between the pair of check valves so as to cause the check valve mounted on the second compartment to open and release from the second compartment an amount of air which has a predetermined ratio to the amount of oxygen passing through the first compartment.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a schematic view of one possible apparatus for carrying out the present invention;

Fig. 2 is a schematic View, partly in section, of a part of the apparatus shown in Fig. 1;

Fig. 3 is an enlarged sectional view of'a part of the apparatus shown in Fig. 1;

Fig. 4 is a schematic view partly in section, of another embodiment of the present invention;

Fig. 5 is partly sectional, fragmentary view of a part of the structure of Fig. 4; and

Fig. 6 is a sectional view of a detail of the apparatus of Fig. 4.

Referring now to the drawings, there is shown in Fig. 1 an air-supply system which includes the housing I in which is located the expansible container 4, which may be formed of any flexible material capable of preventing the escape of a gas therefrom. A conduit 54 leads from the bag 4 to the valve casingli for conveying air from the container 4 through the valve casing Hi to the flexible tube 1 l which leads to a mouthpiece (not shown) so that the user may inhale air from container 4 through members It, It and IL, A flexible tube l2 leads from a mask (not shown) to the conduit I5 so as to carry away exhaled air from the user. This exhaled air passesfrom the 3 conduit I5 through the Cartridge 2, which has a suitable alkali therein for removing carbon di oxide from the exhaled air, which, purified of its carbon dioxide, then passes through the conduit I6 back to the expansible container 4.

One end of a lever H, which is pivotally mounted at an intermediate part thereof, is connected to expansible container 4 (Fig. 2), and the opposite end of this lever I1 is connected to a valve 9 so as to automatically operate the same upon movement of the expansible container 4. This valve 9 controls the flow of oxygen from the oxygen tank 3, this oxygen passing through the tubes, joined by nipple 5, and the pressure reducing valve 8 before it reaches the valve 9. A pressure gauge 6 is interconnected with the tubes through which the oxygen flows to indicate the pressure of the oxygen, and a manual by-pass valve 1 is provided adjacent the pressure reducing valve 8.

As is apparent from Figs. 1 and 2, when the amount of air in the expansiblecontainer 4 is reduced so as to lower the left end of lever H, as viewed in Figs. 1 and 2, sufliciently to cause the latter to open valve 9, oxygen will flow from the tank 3 through the valve 9 to the conduit l8. This conduit l8 leads the oxygen through a pump l3 and from this pump through a conduit I9 to the conduit l4 from which the oxygen flows both to the interior of container 4 and to the user.

The pump l3 communicates also with the conduit I6 by means of a conduit 29 and is provided with a discharge tube 20.

The details of the pump I3 are illustrated in Fig. 3, where it is seen that the oxygen flowing along conduit I8 passes through a nozzle 2| into a compartment 22 located on one side of the flexible diaphragm 23 of the pump. The oxygen in compartment 22 will built up a pressure which will move the diaphragm 23 against the action of Spring 25, located in a second compartment 26 of the pump, because the nozzle 24 provided at the entrance to conduit I!) does not permit the oxygen to flow from chamber 22 at as great a rate as that at which it is supplied thereto. The .1

conduit 29 leading from conduit l6, and through the same from the container 4, communicates with the interior of the second compartment 25 of pump l3 through a check valve 21 urged by a spring against the valve seat 28. At the opposite end of compartment 26 is located a second spring-pressed check valve 30 which only permits air to flow from compartment 26 through the tube 20 to the outer atmosphere. The tube 20 has a nozzle 3| mounted therein to retard the flow or gas from compartment 25, and the sizes of nozzles 3| and 24 are so chosen that the amount of air discharged through tube 20 will be a predetermined fraction of the oxygen introduced through conduits |8 and I 9.

The operation of the above structure is believed to be evident. Because the valve 9 is controlled by the movement of container 4, it is apparent that oxygen will be automatically admitted to the system in accordance with the needs of the particular user of the apparatus so that no excess oxygen is wasted. When the amount of air in the container 4 has decreased sufficiently, the valve 9 will automatically be opened to admit oxygen to the system. The valve 9 and lever [1 may be designed to maintain the oxygen content in the container 4 at any desired percentage. It has been found satisfactory to provide the interior of container 4 with an oxygen content of 50%, for example. The relationship between nozzles 3| and 24 are preferably chosen so as to automatically remove from the system a suflicient amount of air to carry away impurities contained in any oxygen tank so as to prevent the building up of these impurities within the container 4, which would eventually render the air within the same unbreathable. It is known that a tank of oxygen may contain up to 2% of unbreathable gases therein. Thus, if the nozzles 3| and 24 are so chosen that the air discharged from compartment 25 will equal 4% of the oxygen passing through compartment 22, and if the oxygen content of the air in the container 4 is maintained at 50%, as was mentioned above, it is evident that the air discharged through port 20 will automatically carry away 2% of the oxygen supplied from tank 3 and in this way prevent unbreathable impurities from building up within the container 4.

The embodiment of the invention which is illustrated in Figs. 4 and 5 shows the tank 3 connected to the tubes joined by the nipple 5 and provided with pressure gauge 6. The container 4 is connected to a lever I2, similar to lever I1, and this lever automatically operates a valve. The air from the expansible container 4 flows through parts l4, l0 and II, in the same way as described above, and the exhaled air flows through elements I2, I5, 2 and I6 back to the container 4, in the same way as described above.

The essential differences between the embodiments of Figs. 1-3 and Figs. 46 are illustrated in Fig. 5 where it is seen that the lever I 2 carries a threaded adjustable stud |2a which acts against the slidably mounted member 38 connected to the diaphragm 39. This latter diaphragm 39 is connected to a slidably mounted pin 40, of square cross-section, which bears against a valve member 36 urged by a spring to the left, as viewed in Fig. 5, and against valve seat 4|.

The oxygen from the tank 3 flows through the conduit 33 to the chamber 34 from Where it passes through the nozzle 35 to the chamber 31 in which valve 36 is located. When this valve is opened the oxygen then flows to conduit 42 and from the latter to the conduit I8 from where it is supplied to the valve casing I0 and conduit M, in the same way as described above. The oxygen will build up in the chamber 31, while the valve 36 remains closed, and in this way it will act against the flexible diaphragm 44 in the compartment 43 of the pump shown in Fig. 5. The spring 45 in compartment 46 of the pump urges the diaphragm 44 against the action of the pressure in chambers 31 and 43. Compartment 46 communicates through pipe 41 with the valve casing 48 which communicates through conduit 49 with conduit I 5, as shown in Fig. 4, and which communicates through tube 56 with the outer atmosphere. A pair of check valves 5| and 54 are located within the casing 48, the spring 52 urgin the valve disc 5| against a valve seat 53 so as to permit air to flow only from conduit 49 to casing 48, and a spring urging the valve disc 54 against a valve seat to prevent air from entering through the tube 55.

When the valve 35 is opened, the pressure within compartment 43 and chamber 31 will drop so that the diaphragm 44 will be urged toward chamber 31 by spring 45, and in this way air will be drawn into casing 48 and compartment 45 through the valve 5|. When the pressure within compartment 43 and chamber 37 builds up, it will displace a part of the volume of air in casing 48 and compartment 45 through the valve 54 to the outer atmosphere through tube 56. While the pressure in compartment 43 and chamber 3'! changes, the pressure in casing 48 and compartment 46 remains substantially constant, and the only changes taking place in these latter spaces are volumetric. It is believed evident that the construction shown in Fig. 5 will act in the same wayas pump l3 to automatically eliminate from the system an amount of air which has a predetermined ratio to the amount of oxygen drawn into the system.

. The apparatus may be adjusted so that valve 35 opens as soon as 1l liters of air are withdrawn from the expansible container 4. The nozzle 35 is of such size that a quantity of oxygen approximately corresponding to maximum requirements is capable of passing therethrough. A nozzle 51, shown in Fig. 6, may be provided in the conduit 49 to retard the flow of air therethrough so that less air will pass to chamber 48 when the user takes short breaths than when the user takes long deep breaths.

. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of process and apparatus for supplying breathing air difiering from the types described above.

While the invention has been illustrated and described as embodied in a self-sustaining process and apparatus for supplying the breathing air, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will i so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

I.claim:

1; A self-sustaining air-supply apparatus suitable for supplying breathing air comprising, in combination, a container adapted to hold air therein which is suitable for breathing; first duct means communicating with said container for conveying air to be inhaled therefrom to the user; second duct means communicating with said container for conveying air exhaled by the user back tothe container; scavenging means arranged in said second duct means for removing carbon dioxide from the exhaled air before it arrives at said container, said container, duct means, and scavenging means all together forming an airsupply system; supply means communicating with said container for supplying oxygen to said container; and means for removing from said airsupply system an amount of air which has a predetermined ratio to the amount of oxygen supplied by said oxygen supply means, said air-removing means comprising a pump communicating with said container for receiving air from said container on the suction stroke of the pump and communicating with the atmosphere to expel the air received from said container on the exhaust stroke of the pump, and actuating means for the pump operatively connected to said oxygen supply means so as to be controlled by the latter.

2. A self-sustaining air-supply apparatus suitable for supplying breathin air comprising, in combination, an expansible container having air therein which is suitable for breathing; first conduit means communicating at one end with said expansible container for leading air away from said container so that it may be inhaled; second conduit means communicating with said expansible container for guiding exhaled air from the user back to said container; scavenging means mounted in said second conduit means so that the exhaled air passes through said scavenging means and has the carbon dioxide therein removed therefrom by said scavenging means; an oxygen tank; third conduit means leading from said oxygen tank to said first conduit means so as to convey fresh oxygen through said first conduit means to said container and to the user; valve means mounted in said third conduit means for controlling the amount of oxygen removed from said oxygen tank; operating means for controlling said valve means, said operating means being connected to said expansible container so that the movement of said expansible container causes said operating means to open and close said valve means; a pump comprising a chamber and a flexible diaphragm extendin across said chamber so as to divide the same into first and second compartments, said first compartment being located in said third conduit means so that the oxygen released from said tank passes through said first compartment, nozzle means mounted in said third conduit means for causing the oxygen to build up a pressure in said first compartment; fourth conduit means communicating with said container and with the second compartment of said pump so as to convey air from said container to said second compartment; a pair of check valves, one of which is mounted in said fourth conduit means so as to prevent air from leaving said second compartment through said fourth conduit means and the other of said check valves being mounted on said second compartment so as to permit air only to escape from said second compartment to the atmosphere, the building up of pressure by said oxygen in said first compartment causing the diaphragm to compress air trapped between said pair of check valves and causing said other check valve to open and permit the escape from said second compartment of an amount of air which has a predetermined proportion to the amount of oxygen passing through said first compartment. I

3. A self-sustaining air-supply apparatus suitable for supplyin breathing air comprising, in combination, an expansible container having air therein which is suitable for breathing; first conduit means communicating at one end with said expansible container for leading air away from said container so that it may be inhaled; second conduit means communicating with said expansible container for guiding exhaled air from the user back to said container; scavenging means mounted in said second conduit means so that the exhal d air passes through said scavenging means and has the carbon dioxide therein removed therefrom by said scavenging means; an oxygen tank; a pump comprising a chamber and a flexible diaphragm extending across said chamber so as to divide the same into first and second compartments, said first compartment being located in communication with said oxygen tank so that the oxygen released from said tank passes through said first compartment; third conduit means leading from said first compartment to said first conduit means so as to convey fresh oxygen through said first conduit means to said container and to the user; valve means mounted between said first compartment and said third conduit means for controllin the amount of oxygen removed from said oxygen tank, whereby the oxygen pressure in said first compartment of said pump builds up when said valve means is in its closed position; operating means for controlling said valve means, said operating means being connected to said expansible container so that the movement of said expansible container causes said operating means to open and close said valve means; fourth conduit means communicating with said container and with said second compartment of said pump so as to convey air from said container to said second compartment; a pair of check valves one of which is mounted in said fourth conduit means so as to prevent air from leaving said second compartment through said fourth conduit means and the other of said check valves being mounted on said second compartment so as to permit air only to escape from said second compartment to the atmosphere, the building up of pressure by said oxygen in said first compartment causing the diaphragm to compress air trapped between said pair of check valves and causing said other check valve to open and permit the escape from said second compartment of an amount of air which has a predetermined proportion to the amount of oxygen passing through said first compartment.

4. A self-sustaining air-supply apparatus suitable or supplying breathing air comprising, in combination, an expansible container having air therein which is suitable for breathing; first conduit means communicating at one end with said expansible container for leading air away from said container so that it may be inhaled; second conduit means communicating with said expansible container for guiding exhaled air from the user back to said container; scavenging means mounted in said second conduit means so that the exhaled air passes through said scavenging means and has the carbon dioxide therein removed therefrom by said scavenging means; an oxygen tank; a pump comprising a chamber and a flexible diaphragm extending across said chamber so as to divide the same into first and second compartments, said first compartment being located in communication with said oxygen tank so that the oxygen released from said tank passes through said first compartment; third conduit means leading from said first compartment to said first conduit means so as to convey fresh oxygen through said first conduit means to said container and to the user; valve means mounted between said first compartment and said third conduit means for controlling the amount of oxygen removed from said oxygen tank, whereby the oxygen pressure in said first compartment of said pump builds up when said valve means is in its closed position; operating means for controlling said valv means, said operating means being connected to said expansible container so that the movement of said expansible container causes said operating means to open and close said valve means; fourth conduit means communicating with said container and with said second compartment of said pump so as to convey air from said container to said second compartment; a pair of check valves one or" which is mounted in said fourth conduit means so as to prevent air from leaving said second compartment through said fourth conduit means and the other of said check valves being mounted on said second compartment so as to permit air only to escape from said second compartment to the atmosphere, the building up of pressure by said oxygen in said first compartment causing the diaphragm to compress air trapped between said pair of check valves and causing said other check valve to open and permit the escape from said second compartment of an amount of air which has a predetermined proportion to the amount of oxygen passing through said first compartment; and a nozzle mounted in said fourth conduit means between said container and said one check valve for retarding the flow of air through said one check valve to said second compartment of said pump.

5. A self-sustaining air-supply apparatus suitable for supplying breathing air, comprising in combination, a container adapted to hold therein air which is suitable for breathing; first duct means communicating with said container for conveying air to be inhaled therefrom to the user; second duct meansrcommunioating with said con tainer for conveying air exhaled by the user back to said container; scavenging means arranged in said second duct means for removing carbon dioxide from the exhaled air before it arrives at said container; third duct means communicating with said container for conveying oxygen to the same; discharge means operatively connected to said container for discharging air therefrom; and automatic control means operatively connected to said discharge means for operating the same, said automatic control means being arranged in said third duct means to be actuated by oxygen passing therethrough so as to automatically operate said discharge means for discharging from said container an amount of air which has a predetermined ratio to the amount of oxygen conveyed through said third conduit means.

6. A'self-sustaining air supply apparatus suitable for supplying breathing air, comprising, in combination, a container having air therein which is suitable for breathing; first duct means communicating with said container for conveying air to be inhaled therefrom to the user; second duct means communicating with said container for conveying air exhaled by th user back to the container; scavenging means arranged in said second duct means fo removing carbon dioxide from the exhaled air before it arrives at said container, said container, duct means, and scavenging means all together forming an air-supply system; supply means for conveying oxygen to said air supply system; discharge means for removing air from said air-supply system; and control means operatively connected to said discharge means for adjusting the amount of air discharged by the same, said control means being also operatively connected to said supply means to be actuated by the oxygen conveyed by the same to said container so as to operate said discharge means for discharging from said container an amount of air which has a predetermined ratio to the amount of oxygen conveyed by said supply means.

7. A self-sustaining air supply apparatus suitable for supplying breathing air, comprising, in combination, a container having air therein which is suitable for breathing; first duct means communicating with said container for conveying air to be inhaled therefrom to the user; second duct means communicating with said container for conveying air exhaled by the user back to the container; scavenging means arranged in said second duct means for removing carbon dioxide 9 from the exhaled air before it arrives at said REFERENCES CITED contamfer' 531d contamer' duct means, 1 The following references are of record in the scavenging means all together forming an airfile of this patent. supply system; supply means for conveying oxygen to said container; pump means for remov- 5 UNITED STATES PATENTS ing air from said air supply system; and operat- Number Name Date ing means operatively connected to said pump 1,683,144: Schroeden Sept. 4, 1928 means for operating the same, said operating 2,324,389 Heidbrink July 13, 1943 means being operatively connected to said supply 2,441,216 Wiggins May 11, 1948 means to be actuated by the oxygen conveyed by 19 the same to said container so as to operate said FOREIGN PATENTS pump means for pumping from said container an Number Country Date amount of air which has a predetermined ratio 727,795 Germany 1 to the amount of oxygen conveyed by said supply means. 15

FRANZ HOLLMAN N. 

